MSPM0 PMBus Library User’s Guide

1. Introduction

The MSPM0 PMBus Library is based on the MSPM0 SMBus library. The MSPM0 PMBus library provides a set of APIs to communicate over PMBus as a controller or a target.

2. PMBus Library Supported Features

This library was developed in compliance with the PMBus 1.3.1 specification.

2.1 PMBus Supported Features

• Address, memory, communication and capability related commands

• On, off, and margin testing related commands

• Output voltage related commands

• “Other commands” as detailed by the PMBus specification

• Fault related commands

• Power good signal limits

• Output voltage sequencing commands

• Unit status commands

• Parametric information commands

• Manufacturer’s information commands

2.3 PMBus Features Not Currently Implemented

The PMBus features listed below are supported in hardware but have not been implemented in this release:

• ZONE_READ and ZONE_WRITE protocols

3. PMBus Example Usage

This software library contains an example that demonstrate communication between a PMBus Controller and the TPS544B20EVM-634 evaluation module. The example configures the TPS544B20EVM-634’s behavior during under-voltage or over current events.

• pmbus_controller_tps544b20evm

The above example contains source code which can be compiled and loaded onto a supported device as-is. Connect SMBCLK and SMBDAT between the controller and the TPS544B20EVM-634. Ensure properly sized pullup resistors are provisioned.

3.1 PMBus Examples Supported Hardware

• 2 LP-MSPM0L1306 or LP-MSPM0G3507 LaunchPad evaluation boards

4. Library Footprint

The following footprint was obtained with TI Arm Clang compiler v3.2.0 LTS using LP-MSPM0G3507.

PMBus Controller

Example	Module	Optimization Level	Code (bytes)	Const (bytes)	RAM (bytes)	Options
pmbus_controller_tps544b20evm	Total	-O2	2572	323	1279	SMB_CONTROLLER_SUPPORTS_HOST_NOTIFY = true
“	pmbus.o	“	304	0	243	“
“	smbus_nwk.o	“	234	0	0	“
“	smbus_phy.o	“	416	0	0	“
“	smbus.o	“	376	0	0	“
“	dl_i2c.o	“	192	0	0	“
pmbus_controller_tps544b20evm	Total	-Oz -flto*	1734	409	1084	SMB_CONTROLLER_SUPPORTS_HOST_NOTIFY = true
pmbus_controller_tps544b20evm	Total	-O2	2556	323	1279	SMB_CONTROLLER_SUPPORTS_HOST_NOTIFY = false
“	pmbus.o	“	304	0	243	“
“	smbus_nwk.o	“	234	0	0	“
“	smbus_phy.o	“	400	0	0	“
“	smbus.o	“	376	0	0	“
“	dl_i2c.o	“	192	0	0	“
pmbus_controller_tps544b20evm	Total	-Oz -flto*	1718	409	1084	SMB_CONTROLLER_SUPPORTS_HOST_NOTIFY = false

• Note: Individual modules are not shown for LTO optimization since the linker optimizes modules and might skip them in .map file.

5. Library Versions

• Version 1.10.00.00

  • SDK Release: 1.30.00.xx

  • Updates:

    • Updates to use SMBus 1.30.00.xx.

    • Remove unimplemented PMBus_processTimeoutInt.

    • Update examples to use I2C boosterPack standard.

• Version 1.00.00.01

  • SDK Release: 1.10.00.xx

  • Updates:

    • Initial release.